Increased recovery of salmonellae from environmental samples enriched with buffered peptone water

Abstract

The incidence and persistence of salmonellae in weather pools on the top of Stone Mountain were investigated with lactose and buffered peptone water used as pre-enrichment broths. A total of 162 samples were collected from 16 weather pools over a 3-month period. The use of buffered peptone water increased the recovery of salmonellae by approximately 25%. The combined use of direct enrichment in tetrathionate broth containing brilliant green dye and pre-enrichment in buffered peptone water followed by enrichment in tetrathionate broth made it possible to detect all 37 of the contaminated samples. All of the isolates were Salmonella bareilly, the only serotype recovered in a previous study. All but one of the isolations were made from moist or wet samples. S. bareilly was isolated from rabbit dung and litter collected near the weather pools, but attempts to trap rabbits for study were unsuccessful. Random samples taken along a side of the mountain yielded S. bareilly in weather pools within the upper third of the mountain; below this level, S. weslaco and S. memphis were recovered, but not S. bareilly.